Thin film deposition apparatus and thin film deposition method

Abstract

The invention discloses thin film deposition equipment and a deposition method. The thin film deposition equipment comprises a first gas inlet system located at the top in a reaction cavity and used for introducing process gas and a precursor, and the process gas is used for dissociating to generate plasma; and the second gas inlet system is positioned at the bottom in the reaction cavity and is used for introducing current-carrying gas from bottom to top when the precursor is introduced from top to bottom by the first gas inlet system to deposit the conductive film on the wafer, so that the current-carrying gas forms a protective gas curtain in a plasma field in the upper and lower areas of the edge of the wafer. By means of the thin film deposition equipment, the local density of the plasma fields in the upper area and the lower area of the wafer edge in the technological process of conductive thin film deposition can be adjusted, the stability of the plasma fields is improved, and therefore the abnormal discharge phenomenon occurring in the deposition process is reduced, and the film forming quality and the technological stability are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor manufacturing, and in particular to a thin film deposition device, a thin film deposition method, and a computer-readable storage medium. Background Art

[0002] With the development of three-dimensional non-volatile memory technology, the number of stacked silicon carbide and silicon oxide layers will become higher and higher, and the requirements for hard mask plates that are resistant to etching will also become higher and higher. The amorphous carbon film grown by traditional plasma enhanced chemical vapor deposition (PECVD) can no longer meet the demand. In response to this technical demand, it is necessary to develop an amorphous carbon film with stronger etching resistance.

[0003] In the process of depositing an amorphous carbon hard mask by PECVD, in order to obtain an amorphous carbon film with a higher etching selectivity, it is often necessary to deposit under high temperature and high power conditions. For example, the process temperature needs to reach a high temperature of 600-650°C and the power condition needs to reach 2500-5000W.

[0004] Under the harsh process conditions of high temperature and high power, the deposition of conductive amorphous carbon films has extremely high requirements for process stability. Slight changes in the process will cause fluctuations in the plasma field, and the instability of the plasma field will further cause abnormal discharge between the shower plate and the wafer as the upper plate, and between the heating plate and the wafer as the lower plate. In addition, when the film quality is poor, part of the amorphous carbon film will peel off, and the peeled amorphous carbon film will also have abnormal discharge with the upper and lower plates under the action of strong plasma. This abnormal discharge phenomenon is extremely damaging to the wafer and can easily lead to the scrapping of the wafer.

[0005] In order to solve the above-mentioned problems existing in the prior art, the art is in urgent need of a thin film deposition technology that can adjust the local density of the plasma field in the upper and lower areas of the wafer edge during the process of depositing a conductive thin film, improve the stability of the plasma field, thereby reducing the abnormal discharge phenomenon occurring during the deposition process, and improving the film quality and process stability. Summary of the invention

[0006] A brief summary of one or more aspects is given below to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all conceived aspects, and is neither intended to identify the key or decisive elements of all aspects nor to define the scope of any or all aspects. Its only purpose is to give some concepts of one or more aspects in a simplified form as a prelude to a more detailed description that will be given later.

[0007] In order to overcome the above-mentioned defects of the prior art, the present invention provides a thin film deposition device, a thin film deposition method, and a computer-readable storage medium, which can adjust the local density of the plasma field in the upper and lower regions of the wafer edge during the process of depositing a conductive thin film, improve the stability of the plasma field, thereby reducing the abnormal discharge phenomenon occurring during the deposition process, and improving the film quality and process stability.

[0008] Specifically, the above-mentioned thin film deposition equipment provided according to the first aspect of the present invention includes: a first gas intake system, located at the top of the reaction chamber, for introducing process gas and precursor, wherein the process gas is used to dissociate to generate plasma; and a second gas intake system, located at the bottom of the reaction chamber, for introducing carrier gas from bottom to top when the first gas intake system introduces the precursor from top to bottom to deposit a conductive film on the wafer, so that the carrier gas forms a protective gas curtain in the plasma field in the upper and lower areas of the wafer edge.

[0009] Furthermore, in some embodiments of the present invention, the thin film deposition equipment includes an upper electrode plate and a lower electrode plate, the lower electrode plate is located in a heating plate at the bottom, the wafer is supported above the heating plate, the upper electrode plate is located in a shower head at the top, the process gas is dissociated into the plasma in the high-frequency electric field formed between the upper electrode plate and the lower electrode plate, and the second gas intake system is arranged around the bottom of the heating plate so that the carrier gas invades the plasma field in the upper and lower areas of the wafer edge from the bottom to the top from the edge of the heating plate to form a protective gas curtain.

[0010] Furthermore, in some embodiments of the present invention, the second air intake system includes several layers of air distribution rings and air intake rings. After the carrier gas is distributed several times through the several layers of air distribution rings, it is evenly transmitted to the air intake ring and invades the plasma field in the upper and lower areas of the wafer edge from bottom to top from any direction through the air intake holes in the air intake ring.

[0011] Furthermore, in some embodiments of the present invention, the air inlet holes are distributed in the air inlet ring, and the aperture size and / or hole density and / or air inlet angle of the air inlet holes in each area are negatively correlated with the target plasma density in the target area of ​​the plasma field above its corresponding position.

[0012] Furthermore, in some embodiments of the present invention, the second air intake system includes multiple air intake pipes, which are dispersedly connected to the air distribution ring, and each of the air intake pipes is provided with an independent valve for providing the carrier gas with different flow rates from multiple directions to multiple areas in the plasma field above its corresponding position.

[0013] In addition, the above-mentioned thin film deposition method provided according to the second aspect of the present invention includes the following steps: introducing a process gas into a reaction chamber through the first gas intake system in the above-mentioned thin film deposition equipment provided by the first aspect of the present invention to dissociate and generate plasma; introducing a precursor from top to bottom through the first gas intake system to deposit a conductive film on a wafer, and simultaneously introducing a carrier gas from bottom to top through the second gas intake system so that the carrier gas forms a protective gas curtain in the plasma field in the upper and lower regions of the wafer edge.

[0014] Further, in some embodiments of the present invention, the reaction chamber includes a heating plate as a lower electrode, and the second gas intake system is arranged around the bottom of the heating plate, and the precursor is introduced from top to bottom through the first gas intake system to deposit a conductive film on the wafer, and the second gas intake system simultaneously introduces a carrier gas from bottom to top so that the carrier gas forms a protective gas curtain in the plasma field of the upper and lower regions of the wafer edge. The steps include: introducing the precursor carried by at least the first carrier gas from top to bottom through the first gas intake system; introducing the second carrier gas from bottom to top through the second gas intake system so that the second carrier gas invades the plasma field of the upper and lower regions of the wafer edge from bottom to top from the edge of the heating plate to form a protective gas curtain; and adjusting the gas flow rate and / or entry area of ​​the second carrier gas so that the target area of ​​the second carrier gas in the plasma field reaches a target plasma density.

[0015] Further, in some embodiments of the present invention, the step of introducing the second carrier gas from bottom to top through the second gas intake system so that the second carrier gas invades from the edge of the heating plate from bottom to top into the plasma field of the upper and lower regions of the wafer edge to form a protective gas curtain also includes: introducing a mixed gas of the second carrier gas and the third carrier gas from bottom to top through the second gas intake system so that the mixed gas invades from the edge of the heating plate from bottom to top into the plasma field of the upper and lower regions of the wafer edge to form a protective gas curtain; the step of adjusting the gas flow rate and / or entry area of ​​the second carrier gas so that the target region of the second carrier gas in the plasma field reaches a target plasma density includes: adjusting the gas flow rate and / or entry area of ​​the mixed gas so that the target region of the mixed gas in the plasma field reaches a target plasma density.

[0016] Further, in some embodiments of the present invention, the second air intake system includes several layers of air distribution rings and air intake rings, wherein a plurality of air intake pipelines are dispersedly connected to the air distribution rings, and each of the air intake pipelines is provided with an independent valve, the air intake holes are distributed in the air intake rings, and the aperture size and / or aperture density and / or air intake angle of the air intake holes in each area are negatively correlated with the density of the target plasma in the target area of ​​the plasma field above its corresponding position, and the step of adjusting the gas flow rate and / or entry area of ​​the second carrier gas so that the target plasma density of the second carrier gas in the target area of ​​the plasma field reaches the target plasma density includes: determining the aperture size and / or the aperture density and / or the air intake angle of the air intake holes corresponding to the target area according to the target area in the plasma field and the target plasma density; and determining the valve opening of the air intake pipeline connected to the air distribution ring and corresponding to the target area according to the target plasma density, so as to provide the gas flow rate of the second carrier gas or the mixed gas that meets the target plasma density.

[0017] Furthermore, in some embodiments of the present invention, the precursor is propylene, the first carrier gas is helium, the second carrier gas is argon, and the third carrier gas is nitrogen. The step of adjusting the gas flow rate and / or entry area of ​​the mixed gas so that the mixed gas reaches a target plasma density in a target area in the plasma field includes: respectively adjusting the incoming gas flow rates of the argon gas and the nitrogen gas so that the ratio of the propylene, helium, argon and nitrogen in the reaction chamber is adjusted to a target ratio range.

[0018] Furthermore, in some embodiments of the present invention, after the step of introducing the precursor from top to bottom through the first gas intake system to deposit a conductive film on the wafer, and introducing the carrier gas from bottom to top through the second gas intake system at the same time so that the carrier gas forms a protective gas curtain in the plasma field in the upper and lower regions of the wafer edge, the thin film deposition method also includes: introducing a cleaning gas from bottom to top through at least the second gas intake system so that the cleaning gas contacts the conductive film at the edge of the wafer from bottom to top from the edge of the heating plate to perform edge etching on the conductive film.

[0019] In addition, according to the third aspect of the present invention, there is also provided a computer-readable storage medium on which computer instructions are stored. When the computer instructions are executed by a processor, the above-mentioned thin film deposition method provided by the second aspect of the present invention is implemented. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above features and advantages of the present invention can be better understood after reading the detailed description of the embodiments of the present disclosure in conjunction with the following drawings. In the drawings, the components are not necessarily drawn to scale, and components with similar related properties or features may have the same or similar reference numerals.

[0021] Figure 1 A schematic structural diagram of a thin film deposition device provided according to some embodiments of the present invention is shown;

[0022] Figure 2 A schematic structural diagram of a second air intake system provided according to some embodiments of the present invention is shown;

[0023] Figure 3 A flow chart of a thin film deposition method provided according to some embodiments of the present invention is shown;

[0024] Figure 4 A schematic diagram of an air intake process of a second air intake system provided in some embodiments of the present invention is shown;

[0025] Figure 5A A schematic diagram showing the relationship between the nitrogen ratio in the reaction chamber and the film thickness range provided in some embodiments of the present invention is shown;

[0026] Figure 5B A schematic diagram showing the relationship between the nitrogen ratio in the reaction chamber and the extinction coefficient range provided by some embodiments of the present invention; and

[0027] Figure 6 A schematic diagram showing the relationship between the ratio change of argon and nitrogen and the average film thickness at the edge of the wafer according to some embodiments of the present invention is shown.

[0028] Reference numerals:

[0029] 10Thin film deposition equipment;

[0030] 100 reaction chambers;

[0031] 110 first air intake system;

[0032] 120 second air intake system;

[0033] 121 gas rings;

[0034] 122 intake ring;

[0035] 123 air intake;

[0036] 124 air intake pipe;

[0037] 131 sprinkler head;

[0038] 132 heating plate;

[0039] 140 air extraction port;

[0040] Steps S310 to S320;

[0041] Steps S321 to S323;

[0042] Curves 510 and 520; and

[0043] 530, 540 curves. DETAILED DESCRIPTION

[0044] The following specific embodiments illustrate the implementation of the present invention, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this invention are limited to this implementation. On the contrary, the purpose of introducing the invention in conjunction with the implementation is to cover other options or modifications that may be extended based on the claims of the present invention. In order to provide a deep understanding of the present invention, the following description will include many specific details. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present invention, some specific details will be omitted in the description.

[0045] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In addition, the terms "upper", "lower", "left", "right", "top", "bottom", "horizontal" and "vertical" used in the following description should be understood as the directions shown in the paragraph and the related drawings. Such relative terms are only used for the convenience of description and do not mean that the device described therein must be manufactured or operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0047] It is understood that although the terms "first", "second", "third", etc. may be used herein to describe various components, regions, layers and / or parts, these components, regions, layers and / or parts should not be limited by these terms, and these terms are only used to distinguish different components, regions, layers and / or parts. Therefore, the first component, region, layer and / or part discussed below may be referred to as a second component, region, layer and / or part without departing from some embodiments of the present invention.

[0048] As mentioned above, under the harsh process conditions of high temperature and high power, the deposition of conductive amorphous carbon film has extremely high requirements for process stability. Slight changes in the process will cause fluctuations in the plasma field, and the instability of the plasma field will further cause abnormal discharge between the shower plate and the wafer as the upper plate, and between the heating plate and the wafer as the lower plate. In addition, when the film quality is poor, part of the amorphous carbon film will peel off, and the peeled amorphous carbon film will also have abnormal discharge with the upper and lower plates under the action of strong plasma. This abnormal discharge phenomenon is extremely damaging to the wafer and can easily lead to the scrapping of the wafer.

[0049] In order to solve the above-mentioned problems existing in the prior art, the present invention provides a thin film deposition device, a thin film deposition method, and a computer-readable storage medium, which can adjust the local density of the plasma field in the upper and lower regions of the wafer edge during the process of depositing a conductive thin film, improve the stability of the plasma field, thereby reducing the abnormal discharge phenomenon occurring during the deposition process, and improving the film formation quality and process stability.

[0050] In some non-limiting embodiments, the thin film deposition apparatus provided by the first aspect of the present invention may be used to implement the thin film deposition method provided by the second aspect of the present invention.

[0051] Specifically, in some non-limiting embodiments, the computer-readable storage medium provided in the third aspect of the present invention stores computer instructions, which, when executed by a processor, can be used to execute the thin film deposition method provided in the third aspect of the present invention.

[0052] The working principle of the above-mentioned thin film deposition device will be described below in conjunction with some embodiments of the thin film deposition method. Those skilled in the art will understand that these embodiments of the thin film deposition method are only some non-limiting implementation methods provided by the present invention, which are intended to clearly demonstrate the main concept of the present invention and provide some specific solutions that are convenient for the public to implement, rather than to limit all working modes or all functions of the thin film deposition device. Similarly, the thin film deposition device is also only a non-limiting implementation method provided by the present invention, and does not constitute a limitation on the implementation subject of each step in these thin film deposition methods.

[0053] Please see Figure 1 , Figure 1 A schematic structural diagram of a thin film deposition device provided according to some embodiments of the present invention is shown.

[0054] like Figure 1As shown, in some embodiments of the present invention, the thin film deposition device 10 may include a first gas inlet system 110 and a second gas inlet system 120. The first gas inlet system 110 may be located at the top of the reaction chamber 100, and is used to introduce process gases and precursors. The precursor is a gaseous substance containing a thin film material that is adsorbed on the surface of the wafer by physical or chemical means, and different types of thin films may correspond to different precursors. For example, in the deposition process of obtaining an amorphous carbon film, the precursor may be propylene (C 3 H 6 ). The process gas can be used to dissociate in a high frequency electric field to generate plasma. In the reaction chamber 100, the plasma field environment can enhance the chemical activity of the precursor, which is conducive to the adsorption of the precursor on the wafer surface for thin film deposition.

[0055] Alternatively, if Figure 1 As shown, the process gas and the precursor may be introduced through two gas inlets in the first gas inlet system 110 , respectively.

[0056] Continue as Figure 1 As shown, the second gas inlet system 120 can be located at the bottom of the reaction chamber 100, and is used to introduce a carrier gas from bottom to top when the first gas inlet system 110 introduces a precursor from top to bottom to deposit a conductive film on the wafer, so that the carrier gas forms a protective gas curtain in the plasma field above the wafer. The carrier gas is usually selected from an inert gas that is difficult to dissociate, such as argon, helium, nitrogen and other inactive gases, so that the protective gas curtain can be adjusted in the plasma field above and below the edge of the wafer, the density in the plasma field can be locally adjusted, and the plasma field can be stabilized.

[0057] Specifically, if Figure 1 As shown, the reaction chamber 100 of the thin film deposition equipment 10 may also include a shower head 131 located at the top and a heating plate 132 located at the bottom. The shower head 131 can be used to pass the gas required for the reaction from top to bottom. The top of the heating plate 132 is used to support the wafer. In addition, the shower head 131 may include an upper electrode plate, and the heating plate 132 may include a lower electrode plate. In this embodiment, by applying a high-frequency power supply to the heating plate 132, a high-frequency electric field can be formed between the upper and lower electrodes to dissociate the process gas to generate plasma and form a plasma field. Under the action of the plasma field, propylene deposits an amorphous carbon film (amorphous carbon film) on the surface of the wafer.

[0058] For further information, see Figure 2 , Figure 2 A schematic structural diagram of a second air intake system provided according to some embodiments of the present invention is shown.

[0059] Combination Figure 1 and Figure 2As shown, the second gas inlet system 120 can be disposed around the bottom of the heating plate 132 so that the carrier gas intrudes from the edge of the heating plate 132 from bottom to top into the plasma field above and below the edge of the wafer to form a protective gas curtain.

[0060] Specifically, the second air intake system 120 may further include an air splitter ring 121, an air intake ring 122, and an air intake pipeline 124. Figure 2 As shown, the carrier gas can enter the bottom of the reaction chamber 100 through the bottom air inlet pipe 124, and then be divided into two parts by the gas dividing ring 121 (which can be understood in combination with the gas flow direction) and evenly transmitted to the air inlet ring 122, and then through the air inlet hole 123 in the air inlet ring 122, it can invade from any direction from bottom to top into the area between the edge of the wafer and the upper electrode shower head 131, and between the edge of the wafer and the lower electrode heating plate 132, that is, the plasma field of the upper and lower areas of the edge of the wafer, thereby adjusting the plasma density of the upper and lower areas of the edge of the wafer and stabilizing the plasma field of the upper and lower areas of the edge.

[0061] Alternatively, if Figure 2 As shown, the second gas inlet system 120 may also include multiple gas splitting rings 121, for example, multiple gas splitting rings 121 divided into two into four, four into eight, eight into sixteen, etc. By stacking and matching multiple gas splitting rings 121, for example, a gas splitting ring divided into two may be connected to a gas splitting ring divided into four above, so that the carrier gas is gradually split, so that the carrier gas that finally enters the reaction chamber 100 from bottom to top is more uniform, so that the plasma field in the upper and lower regions of the wafer edge can also be more stable and uniform, which is conducive to improving the uniformity of the thin film.

[0062] Further, continue as Figure 2 As shown, the inlet holes 123 can be evenly or unevenly distributed in the inlet ring 122, so that the carrier gas can enter the upper and lower regions of the wafer edge evenly or unevenly according to the film performance requirements. Specifically, the aperture size and / or hole position density and / or inlet angle of the inlet holes 123 in each region can be negatively correlated with the target plasma density in the target region of the plasma field above the corresponding position.

[0063] For example, the smaller the target plasma density requirement in the target area of ​​the plasma field above the corresponding position, the larger the aperture size of the inlet holes 123 in this area of ​​the inlet ring 122, which is used to pass more difficult-to-dissociate carrier gas into the target area, thereby forming a protective gas curtain above the target area. Optionally, at this time, the hole position density of the inlet holes 123 in this area of ​​the inlet ring 122 can also be distributed more densely, and the inlet angle can also be more toward the target area, so as to pass more carrier gas into the target area to form a protective gas curtain in the target area. It can be understood that the above-mentioned aperture size and / or hole position density and / or inlet angle of the inlet holes 123 in the inlet ring 122 in this embodiment can be adjusted accordingly according to the process requirements, so as to change the gas flow field at the bottom of the reaction chamber 100, thereby changing the electric field or plasma field distribution inside the cavity.

[0064] Optionally, in some embodiments, the air inlet holes 123 in the air inlet ring 122 may be arranged in a single row or multiple rows according to process requirements.

[0065] Furthermore, continue as Figure 2 As shown, the second air intake system 120 may also include a plurality of air intake pipes 124. The plurality of air intake pipes 124 may be dispersedly connected to the air distribution ring 121, and each air intake pipe 124 may be provided with an independent valve for providing carrier gas with different flow rates from multiple directions to multiple areas in the plasma field above its corresponding position. In this embodiment, according to the process requirements, the carrier gas entering from the bottom may be uniformly controlled or individually controlled through a single or multiple air intake pipes 124, so as to achieve the purpose of making the local plasma field in the upper and lower areas of the wafer edge more dense or dispersed, thereby improving the film properties of the local area, increasing the process adjustment window, and saving the cost of hardware modification.

[0066] Continue back Figure 1 As shown, in some embodiments, the reaction chamber 100 may further include an annular exhaust port 140, and the annular exhaust port 140 may be arranged around the heating disk 132. When the first air intake system 110 introduces the precursor from top to bottom to deposit the conductive film on the wafer, the second air intake system 120 introduces the carrier gas from bottom to top, so that the carrier gas forms a protective gas curtain in the plasma field above the wafer. At this time, the protective gas curtain can also block the particles falling in the reaction chamber 100 during the deposition process, preventing the particles from falling on the conductive film and affecting the quality of the film. In addition, after the thin film deposition process is completed, the particles above the heating disk 132 in the reaction chamber 100 can be extracted through the annular exhaust port 140, thereby further preventing the particles from falling to the bottom of the reaction chamber 100 and causing bottom contamination of the chamber.

[0067] In addition, since the gas introduced from the bottom through the second gas inlet system 120 partially invades the plasma field between the heating plate 132 and the shower head 131, and the influence on the plasma field is different depending on the type of gas introduced, the plasma intensity can be locally enhanced or weakened, thereby changing the film performance in the local area and adjusting according to the process requirements. When the plasma field becomes more dense, the density and hardness of the film can be higher, and it is less likely to fall off, and the deposition rate of the film can also be increased.

[0068] In this regard, the working principle of the thin film deposition device 10 will be further described below in conjunction with the thin film deposition method provided in another aspect of the present invention. Figure 3 , Figure 3 A flow chart of a thin film deposition method provided according to some embodiments of the present invention is shown.

[0069] like Figure 3 As shown, in some embodiments of the present invention, the thin film deposition method may include the following steps, step S310 and step S320. First, step S310 may be performed: a process gas is introduced into the reaction chamber via a first gas inlet system in the thin film deposition device to dissociate and generate plasma.

[0070] Specifically, please combine Figure 1 It is commonly understood that in some embodiments, during the deposition of a high-temperature amorphous carbon film using PECVD, a process gas may be introduced into the reaction chamber 100 via the first gas inlet system 110. Then, by applying a high-frequency power supply to the heating disk 132, a high-frequency electric field may be formed between the upper and lower plates to dissociate the process gas to generate plasma and form a plasma field.

[0071] Then, step S2320 can be executed: the precursor is introduced from top to bottom through the first gas intake system to deposit a conductive film on the wafer, and the carrier gas is introduced from bottom to top through the second gas intake system to form a protective gas curtain in the plasma field in the upper and lower areas of the wafer edge.

[0072] Specifically, please combine Figure 1 It is commonly understood that in some embodiments, the reaction chamber 100 may include a heating plate 132 as a lower electrode for supporting the wafer. In addition, the second air intake system 120 may be disposed around the bottom of the heating plate 132. Specifically, as Figure 4 As shown, step S320 can be embodied as steps S321 to S323.

[0073] like Figure 4 As shown, first, step S321 may be performed: a precursor carried by at least a first carrier gas is introduced from top to bottom through a first air inlet system.

[0074] In some optional embodiments, during the deposition of the high temperature amorphous carbon film, propylene can be selected as a precursor, and the propylene can be carried into the reaction chamber 100 at least via the first carrier gas. For example, the first carrier gas can be helium, or a carrier gas mixture of helium and argon.

[0075] Then, step S322 may be performed: introducing a second carrier gas from bottom to top through a second gas inlet system, so that the second carrier gas intrudes from the edge of the heating plate from bottom to top into the plasma field in the upper and lower regions of the wafer edge to form a protective gas curtain.

[0076] In some optional embodiments, the second gas inlet system 120 may include a gas splitting ring 121, an inlet ring 122, and an inlet line 124, which are used to pass the second carrier gas from the bottom to the plasma field above the wafer. The second carrier gas can be either argon or nitrogen. After the second carrier gas enters the bottom of the reaction chamber 100 through the inlet line 124 at the bottom, it is divided into two (which can be understood in combination with the gas flow direction) through the gas splitting ring 121 and evenly transmitted to the inlet ring 122, and then the inlet hole 123 in the inlet ring 122 can invade the plasma field of the upper and lower areas of the wafer edge from any direction from bottom to top to form a protective gas curtain. Afterwards, step S223 can be performed to adjust the gas flow rate and / or entry area of ​​the second carrier gas so that the target area of ​​the second carrier gas in the plasma field reaches the target plasma density.

[0077] In the above embodiment, a single carrier gas can be introduced from the bottom through the second air intake system 120, so that the gas flow rate of a carrier gas can be specifically adjusted to reach the flow limit value.

[0078] In some other optional embodiments, the second gas inlet system 120 can also introduce a mixed gas of multiple carrier gases from the bottom, for example, a mixed gas of a second carrier gas and a third carrier gas, wherein the second carrier gas and the third carrier gas can be selected from argon and nitrogen respectively. The gas flow path of the mixed gas from bottom to top is the same as the gas flow path of the single second carrier gas mentioned above, and will not be repeated here. Afterwards, step S323 can be performed to adjust the gas flow rate and / or entry area of ​​the mixed gas so that the mixed gas reaches the target plasma density in the target area in the plasma field.

[0079] In the above embodiment, a mixed carrier gas is introduced from the bottom through the second air inlet system 120, so that the flow ratio of multiple carrier gases can be synchronously adjusted according to the implementation morphology of thin film deposition, so as to adjust the concentration of the plasma field in the local area, thereby changing the carbon film deposition speed in the local area, which is beneficial to improving the uniformity of the thin film.

[0080] Specifically, if Figure 1As shown, since the second air intake system 120 in the thin film deposition device 10 may include several layers of air splitting rings 121 and air intake rings 122, wherein a plurality of air intake pipelines 124 may be dispersedly connected to the air splitting ring 121, and each air intake pipeline 124 may be provided with an independent valve. In addition, the air intake holes 123 may be evenly or unevenly distributed in the air intake ring 122, and the aperture size and / or hole position density and / or air intake angle of each area of ​​the air intake holes are negatively correlated with the density of the target plasma in the target area of ​​the plasma field above the corresponding position. The above step S323 may be further implemented by the following process.

[0081] First, the aperture size and / or hole position density and / or intake angle of the air inlet hole 123 corresponding to the target area can be determined according to the target area and the target plasma density in the plasma field. For example, the smaller the target plasma density requirement in the target area of ​​the plasma field above the corresponding position, the larger the aperture size of the air inlet hole 123 in this area of ​​the air inlet ring 122 is, which is used to pass more carrier gas that is difficult to dissociate into the target area, thereby forming a protective gas curtain above the target area. Optionally, at this time, the hole position density of the air inlet hole 123 in this area of ​​the air inlet ring 122 can also be more densely distributed, and the intake angle can also be more toward the target area, which is used to pass more carrier gas into the target area to form a protective gas curtain in the target area. Then, according to the target plasma density, the valve opening of the air inlet line 124 connected to the gas distribution ring 121 and corresponding to the target area can be determined to provide a gas flow rate of the second carrier gas or mixed gas that meets the target plasma density.

[0082] In the deposition process of the amorphous carbon film of the present invention, the gas type and flow rate of the precursor and the carrier gas will affect the film quality of the amorphous carbon film. When the film quality is poor, part of the amorphous carbon film will be peeled off, and the peeled amorphous carbon film will have abnormal discharge with the upper and lower plates under the action of strong plasma.

[0083] In some optional embodiments, during the deposition of the amorphous carbon film, the precursor may be propylene, the first carrier gas may be helium (He), the second carrier gas may be argon (Ar), and the third carrier gas may be nitrogen (N 2 ). The specific gases corresponding to the first carrier gas to the third carrier gas are not strictly limited. Optionally, the first carrier gas may be argon, and the second carrier gas may be nitrogen.

[0084] Since both the first gas inlet system 110 and the second gas inlet system 120 are used to introduce the precursor and carrier gas required for the reaction into the reaction chamber 100, in some preferred embodiments, the above step S323 may also include adjusting the gas flow rates of argon and nitrogen respectively, so that the ratio of propylene, helium, argon and nitrogen in the reaction chamber 100 is adjusted to a target ratio range.

[0085] Specifically, the initial precursor gas C introduced into the reaction chamber 100 3 H 6 The gas flow rate of the initial first carrier gas He can be in the range of 100-400 sccm, the gas flow rate of the initial second carrier gas Ar can be in the range of 0-12000 sccm, and the gas flow rate of the initial third carrier gas N can be in the range of 0-3000 sccm. 2 The gas flow rate can be in the range of 0-6000sccm. The gas pressure in the reaction chamber can be adjusted to 7-11Torr, the excitation power is 500-3500W, and the reaction temperature is 650 degrees to form an amorphous carbon film in the vacuum reaction chamber 100. When the gas C in the reaction chamber 100 3 H 6 :He:Ar:N 2 In the process of gradually adjusting the ratio from 1:1:20:0 to 1:1:0:20, the deposition quality of the amorphous carbon film is gradually improved and the discharge phenomenon ratio is also improved.

[0086] Furthermore, when the gas C in the reaction chamber 100 3 H 6 :He:Ar:N 2 When the ratio of the gas to the reaction chamber 100 is adjusted to a suitable ratio, the discharge phenomenon ratio can be reduced by more than 99%. At the same time, during the process of adjusting the gas ratio in the reaction chamber 100, the uniformity of the film will also be improved to a certain extent.

[0087] In addition, further, in some optional embodiments, after completing the above step S320, the thin film deposition method also includes: introducing a cleaning gas from bottom to top through at least the second air intake system 120, so that the cleaning gas can contact the conductive film at the edge of the wafer from bottom to top from the edge of the heating plate to perform edge etching on the conductive film.

[0088] In the above-mentioned embodiment of the present invention, by adding a second air intake system 120 at the bottom of the reaction chamber 100, during the deposition of the amorphous carbon film, the reaction gas, including the precursor and the carrier gas, can be introduced from the top and bottom of the chamber at the same time. Further, on this basis, in some optional embodiments, by introducing a single carrier gas or a mixture of multiple carrier gases at the bottom, the type and flow rate of the carrier gas are adjusted to improve the film quality of the amorphous carbon film, reduce the peeling of the amorphous carbon film, and further reduce the occurrence of abnormal discharge. The traditional single-flow reaction gas intake method from top to bottom cannot adjust the plasma concentration in a local area, such as the edge of the wafer, so there are few ways to adjust the morphology of the film, and the uniformity of the generated film is poor.

[0089] Furthermore, in some preferred embodiments of the present invention, the intake flow rates of the first intake system 110 and the second intake system 120 can be adjusted simultaneously through the control switches at the top and the bottom, that is, the intake gas flow rates can be adjusted from the top and the bottom at the same time, so that the modulation capability of the plasma field will be stronger and it is easier to meet the process requirements. Furthermore, each gas in the first intake system 110 and the second intake system 120 can have an independent control flow switch to open or close the control gas type and flow rate according to the requirements.

[0090] In some other optional embodiments, the second air inlet system 120 may also introduce the precursor from the bottom upward to increase the film thickness in the local area above the wafer.

[0091] In the prior art, the types and flow rates of the carrier gas and the precursor are fixed, and the plasma field under this condition is unstable, and discharge is prone to occur. In the present invention, the stability of the plasma field can be improved by adjusting the types and flow rates of the carrier gas and the precursor, thereby improving the film quality of the carbon film and reducing the discharge phenomenon caused by film peeling. In addition, the types and flow directions of the carrier gas and the precursor in the prior art are fixed, and the plasma concentration in the local area cannot be adjusted, resulting in the morphology of the film being unadjustable and the film uniformity being poor. In the present invention, the flow direction and mixing ratio of the carrier gas and the precursor can be changed, thereby changing the concentration of the plasma field in the local area, and then changing the deposition rate of the carbon film in the local area, which can improve the uniformity of the film to a certain extent.

[0092] Next, some specific embodiments will be used to illustrate that different types of introduced carrier gases have different effects on the plasma field, so that the plasma intensity can be locally enhanced or weakened.

[0093] In an optional embodiment, the diameter of the heating plate 132 in the reaction chamber 100 is 330 mm. The initial carrier gas in the reaction chamber 100 is only argon (i.e., 100% Ar). At this time, the electron density of the edge surface of the wafer on the heating plate 132 is 2.92×10 16 m -3 , and the maximum electric field norm on the wafer edge surface is 2.86×10 5 V / m. As nitrogen is introduced from the bottom, the proportion of argon decreases. When the ratio of argon to nitrogen in the reaction chamber 100 is adjusted to 7:3, and nitrogen is evenly distributed on the edge of the wafer through the second gas inlet system 120, the electron density on the edge of the wafer on the heating plate 132 changes to 2.28×10 16 m -3 , and the maximum electric field norm change on the wafer edge surface is 2.49×10 5 V / m. Further, if nitrogen (i.e. 100% N 2 ), the electron density at the edge of the wafer on the heating plate 132 is reduced to 1.44×10 16 m -3 , there will be fewer electrons invading the notch between the wafer edge and the heating plate 132, and the maximum electric field norm on the wafer edge surface is 2.29×10 5 V / m, which is 20% smaller than the maximum electric field norm when the argon ratio is 100%.

[0094] Similarly, in another specific embodiment, the diameter of the heating plate 132 in the reaction chamber 100 is 363 mm. The initial carrier gas in the reaction chamber 100 is only argon (i.e., 100% Ar). At this time, the electron density of the edge surface of the wafer on the heating plate 132 is 2.27×10 16 m -3 , and the maximum electric field norm on the wafer edge surface is 2.17×10 5 V / m. As nitrogen is introduced from the bottom, the proportion of argon decreases. When the ratio of argon to nitrogen in the reaction chamber 100 is adjusted to 7:3, and nitrogen is evenly distributed on the edge of the wafer through the second gas inlet system 120, the electron density on the edge of the wafer on the heating plate 132 changes to 2×10 16 m -3 , and the maximum electric field norm change on the wafer edge surface is 2.15×10 5 V / m. Further, if nitrogen (i.e. 100% N 2 ), the electron density at the edge of the wafer on the heating plate 132 is reduced to 1.25×10 16 m -3, there will be fewer electrons invading the notch between the wafer edge and the heating plate 132, and the maximum electric field norm on the wafer edge surface is 1.85×10 5 V / m, which is 14.7% smaller than the maximum electric field norm when the argon ratio is 100%.

[0095] According to the above two specific embodiments, it can be concluded that as the type of carrier gas entering from the bottom changes and the ratio of the gas flow rate changes (for example, argon gradually decreases and nitrogen gradually increases), the electron density of the plasma field at the edge of the heating disk will change (for example, the electron density will weaken).

[0096] For further information, see Figure 5A and Figure 5B , Figure 5A A schematic diagram showing the relationship between the nitrogen ratio in the reaction chamber and the film thickness range provided in some embodiments of the present invention is shown. Figure 5B A schematic diagram showing the relationship between the nitrogen ratio in the reaction chamber and the extinction coefficient range provided according to some embodiments of the present invention is shown.

[0097] like Figure 5A As shown, the two curves represent normalized film thickness curves under different nitrogen ratios. Curve 510 represents the film thickness range data before the improvement of the bottom nitrogen introduction step, and the normalized film thickness range is approximately between 1 and 1.1. Curve 520 represents the film thickness range data after the bottom nitrogen introduction step is improved, and the normalized film thickness range is reduced to between 0.94 and 1. From the comparison between the above curves 510 and 520, it can be concluded that by introducing nitrogen from the bottom in the present invention to adjust the gas ratio in the reaction chamber, the film thickness range becomes smaller, thereby improving the uniformity of the film.

[0098] like Figure 5B As shown, the two curves represent the normalized curves of the extinction coefficient of the film under different nitrogen ratios. Curve 530 represents the extinction coefficient range data before the improvement of the bottom nitrogen introduction step, and the normalized extinction coefficient range is approximately between 0.95 and 1.01. Curve 540 represents the extinction coefficient range data after the improvement of the bottom nitrogen introduction step, and the normalized extinction coefficient range is reduced to between 0.98 and 1.01. From the comparison of the above curves 530 and 540, it can be concluded that by introducing nitrogen from the bottom in the present invention to adjust the gas ratio in the reaction chamber, the extinction coefficient range becomes smaller, thereby improving the density of the film.

[0099] For further information, see Figure 6 , Figure 6 A schematic diagram showing the relationship between the ratio change of argon and nitrogen and the average film thickness at the edge of the wafer according to some embodiments of the present invention is shown.

[0100] Figure 6 The 0 in the horizontal axis represents the position of the outermost edge of the wafer placed on the heating plate, the left side represents the distance from the edge of the wafer to the upper surface of the wafer, and the right side represents the distance from the edge of the wafer to the lower surface of the heating plate, that is, the distance from the outermost edge of the wafer to the upper and lower dividing points of the wafer. Figure 6 The vertical axis in the figure is the average thickness of the film growth. Figure 6 As shown in the figure, the four curves respectively show that the thickness of the wafer edge area changes with the different ratios of the mixed gas of nitrogen and argon. 2 The ratio of Ar and N at the bottom can be adjusted according to the needs. 2 proportion.

[0101] Through the above embodiments provided by the present invention, the present invention can not only improve the stability of the plasma field or change the electric field strength of a local area in the cavity, thereby improving the film quality of the carbon film, but also reduce the discharge phenomenon caused by film peeling or excessive electric field strength in certain areas, thereby greatly improving the process stability, and can reduce the proportion of discharge phenomena by 99%. At the same time, it can also change the morphology of the amorphous carbon film and improve the thickness uniformity of the carbon film by about 1% to 2%.

[0102] Although the above methods are illustrated and described as a series of actions for simplicity of explanation, it should be understood and appreciated that these methods are not limited by the order of the actions, because according to one or more embodiments, some actions may occur in a different order and / or concurrently with other actions from those illustrated and described herein or not illustrated and described herein but understandable to those skilled in the art.

[0103] Those skilled in the art will further appreciate that the steps of the methods or algorithms described in conjunction with the embodiments disclosed herein may be directly embodied in hardware, in a software module executed by a processor, or in a combination of the two. The software module may reside in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor so that the processor can read and write information from / to the storage medium. In an alternative, a storage medium may be integrated into a processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In an alternative, the processor and the storage medium may reside in a user terminal as discrete components.

[0104] In one or more exemplary embodiments, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented as a computer program product in software, each function may be stored on or transmitted by a computer-readable medium as one or more instructions or codes. Computer-readable media include both computer storage media and communication media, including any medium that facilitates the transfer of a computer program from one place to another. Storage media may be any available medium that can be accessed by a computer. As an example and not limitation, such a computer-readable medium may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, disk storage or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of an instruction or data structure and can be accessed by a computer. Any connection is also properly referred to as a computer-readable medium. For example, if the software is transmitted from a website, a server, or other remote source using a coaxial cable, a fiber optic cable, a twisted pair, a digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwaves, the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwaves are included in the definition of the medium. Disk and disc as used herein include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc, wherein disk often reproduces data magnetically, while disc reproduces data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0105] In summary, the present invention provides a thin film deposition device, a thin film deposition method, and a computer-readable storage medium, which can adjust the local density of the plasma field during the process of depositing a conductive thin film, improve the stability of the plasma field, thereby reducing abnormal discharge phenomena occurring during the deposition process, and improving the film quality and process stability.

[0106] The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein, but should be granted the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A thin film deposition device, characterized in that: include: A first gas inlet system, located at the top of the reaction chamber, for introducing process gas and precursor, wherein the process gas is used for dissociation to generate plasma; as well as The second gas inlet system is located at the bottom of the reaction chamber and is used to introduce a carrier gas from bottom to top when the first gas inlet system introduces the precursor from top to bottom to deposit a conductive film on the wafer, so that the carrier gas forms a protective gas curtain in the plasma field in the upper and lower areas of the wafer edge.

2. The thin film deposition device according to claim 1, characterized in that: The process gas is dissociated into the plasma in the high-frequency electric field formed between the upper plate and the lower plate, and the wafer is supported on the upper plate. The second air inlet system is disposed around the bottom of the heating plate, so that the carrier gas intrudes from the edge of the heating plate from bottom to top into the plasma field of the upper and lower regions of the wafer edge to form a protective air curtain.

3. The thin film deposition device according to claim 2, characterized in that: The second air intake system includes several layers of air distribution rings and air intake rings. After the carrier gas is distributed several times by the several layers of air distribution rings, it is evenly transmitted to the air intake ring and invades the plasma field in the upper and lower areas of the wafer edge from bottom to top from any direction through the air intake holes in the air intake ring.

4. The thin film deposition device according to claim 3, characterized in that: The air inlet holes are distributed in the air inlet ring, and the aperture size and / or hole position density and / or air inlet angle of the air inlet holes in each area are negatively correlated with the target plasma density in the target area of ​​the plasma field above the corresponding position.

5. The thin film deposition device according to claim 3, characterized in that: The second air intake system includes a plurality of air intake pipelines which are dispersedly connected to the air distribution rings, and each of the air intake pipelines is provided with an independent valve for providing the carrier gas with different flow rates from multiple directions to multiple areas in the plasma field above its corresponding position.

6. A thin film deposition method, characterized in that: The following steps are involved: Through the first gas inlet system in the thin film deposition apparatus according to any one of claims 1 to 5, introducing a process gas into the reaction chamber to dissociate and generate plasma; The precursor is introduced from top to bottom through the first gas inlet system to deposit a conductive film on the wafer, and the second gas inlet system simultaneously introduces a carrier gas from bottom to top so that the carrier gas forms a protective gas curtain in the plasma field in the upper and lower regions of the wafer edge.

7. The thin film deposition method according to claim 6, wherein: The reaction chamber includes a heating plate as a lower electrode, and the second air intake system is disposed around and below the heating plate. The step of introducing the precursor from top to bottom through the first gas inlet system to deposit a conductive film on the wafer, and introducing the carrier gas from bottom to top through the second gas inlet system at the same time so that the carrier gas forms a protective gas curtain in the plasma field above and below the edge of the wafer comprises: The precursor carried by at least a first carrier gas is introduced from top to bottom through the first gas inlet system; A second carrier gas is introduced from bottom to top through the second gas inlet system, so that the second carrier gas invades the plasma field of the upper and lower regions of the wafer edge from bottom to top from the edge of the heating plate to form a protective gas curtain; and The gas flow rate and / or the entry area of ​​the second carrier gas are adjusted so that the second carrier gas reaches a target plasma density in a target area of ​​the plasma field.

8. The thin film deposition method according to claim 7, characterized in that: The step of introducing the second carrier gas from bottom to top through the second gas inlet system so that the second carrier gas invades the plasma field of the upper and lower regions of the wafer edge from bottom to top from the edge of the heating plate to form a protective gas curtain also includes: A mixed gas of the second carrier gas and the third carrier gas is introduced from bottom to top through the second gas inlet system, so that the mixed gas invades the plasma field of the upper and lower regions of the wafer edge from bottom to top from the edge of the heating plate to form a protective gas curtain, The step of adjusting the gas flow rate and / or the entry area of ​​the second carrier gas so that the target area of ​​the second carrier gas in the plasma field reaches a target plasma density comprises: The gas flow rate and / or the entry area of ​​the mixed gas are adjusted so that the mixed gas reaches a target plasma density in a target area of ​​the plasma field.

9. The thin film deposition method according to claim 8, characterized in that: The second air intake system comprises several layers of air distribution rings and air intake rings, wherein a plurality of air intake pipelines are dispersedly connected to the air distribution rings, and each of the air intake pipelines is provided with an independent valve, the air intake holes are distributed in the air intake rings, and the aperture size and / or hole position density and / or air intake angle of the air intake holes in each area are negatively correlated with the density of the target plasma in the target area of ​​the plasma field above the corresponding position thereof, The step of adjusting the gas flow rate and / or the entry area of ​​the second carrier gas so that the target area of ​​the second carrier gas in the plasma field reaches a target plasma density comprises: Determining the aperture size and / or the aperture density and / or the air intake angle of the air inlet holes corresponding to the target area according to the target area in the plasma field and the target plasma density; and According to the target plasma density, the valve opening of the gas inlet pipeline connected to the gas distribution ring and corresponding to the target area is determined to provide a gas flow rate of the second carrier gas or the mixed gas that meets the target plasma density.

10. The thin film deposition method according to claim 8, characterized in that: The precursor is propylene, the first carrier gas is helium, the second carrier gas is argon, and the third carrier gas is nitrogen. The step of adjusting the gas flow rate and / or the entry area of ​​the mixed gas so that the mixed gas reaches a target plasma density in a target area of ​​the plasma field comprises: The inlet gas flow rates of the argon gas and the nitrogen gas are adjusted respectively, so that the ratio of the propylene, the helium, the argon gas and the nitrogen in the reaction chamber is adjusted to a target ratio range.

11. The thin film deposition method according to claim 7, characterized in that: After the step of introducing the precursor from top to bottom through the first gas inlet system to deposit a conductive film on the wafer, and introducing the carrier gas from bottom to top through the second gas inlet system so that the carrier gas forms a protective gas curtain in the plasma field above and below the edge of the wafer, the thin film deposition method further includes: Cleaning gas is introduced from bottom to top at least through the second gas inlet system, so that the cleaning gas contacts the conductive film at the edge of the wafer from bottom to top from the edge of the heating plate, so as to perform edge etching on the conductive film.

12. A computer-readable storage medium having computer instructions stored thereon, characterized in that: When the computer instructions are executed by a processor, the thin film deposition method according to any one of claims 6 to 11 is implemented.

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